Jay Sekulow, an attorney for President Donald Trump, said a controversial meeting that took place last year between Donald Trump Jr., other campaign associates and a Russian lawyer was "not illegal" and denied that Donald Trump Sr. had any involvement in or prior knowledge of it.

"The president wasn't aware of the meeting, did not participate in the meeting, did not attend the meeting," Sekulow added.

When pressed whether Trump believed the meeting was appropriate, Sekulow said, "I haven't had the conversation with the president whether he thought it was appropriate or not. Here's what I will tell you: The meeting that took place is not illegal. These kind of meetings take place."

On Tuesday, Donald Trump Jr. tweeted four pages of what he said was an email exchange with publicist Rob Goldstone in June 2016. The messages appear to show Goldstone saying the "Crown prosecutor of Russia" could provide damaging information about Democratic candidate Hillary Clinton in the heat of the 2016 presidential race. In response, Donald Trump Jr. wrote, "I love it."

The emails preceded a meeting at Trump Tower in New York City with the Russian attorney, Natalia Veselnitskaya. Donald Trump Sr.'s then-campaign chairman, Paul Manafort, and son-in-law, Jared Kushner, also attended.

In an interview that aired Tuesday night with Fox News' Sean Hannity, Donald Trump Jr. expressed regret for how he handled the meeting with Veselnitskaya, saying he "probably would have done things a little differently." He maintained that his father had had no knowledge of the encounter.

In a statement Tuesday, Donald Trump Jr. said Veselnitskaya had "no information to provide."

The president defended his eldest son, saying in a statement Tuesday, "My son is a high-quality person, and I applaud his transparency."

In the interview on "GMA," Sekulow reiterated that Donald Trump Sr. did not attend and hadn't been aware of the 20-minute meeting "until very recently" and did not see the email chain until Tuesday, when his son tweeted it. None of this, Sekulow said, was in violation of the law.

"The meeting itself and what took place at the meeting doesn't violate the law. The president was not aware of it. Donald Trump Jr. said in retrospect he would look at it differently today. But you've got to put yourself in the position they were in," Sekulow said. "They're in the middle of a campaign for the presidency of the United States."